纳米复合材料-英文版-05.pdf

《纳米复合材料-英文版-05.pdf》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。

1、2011/2/13CharacterisationofNanofillersandNanocompositesMECH548DepartmentofMechanicalEngineeringHongKongUniversityofScience&Technology1Outline•KeyStepsinDevelopingNanomodifiedMaterials•ChallengesinCharacterizingNano-sizedMaterials•CommonCharacterizationTechniquesforNanocomposites–Wide-angleX-rayDiff

2、raction(WAXD)–ScanningElectronMicroscope–TransmissionElectronMicroscopy(TEM)–X-rayPhotoelectronSpectroscopy(XPS)–Time-of-FlightSecondaryIonMassSpectrometry(ToF-SIMS)–RamanSpectroscopy–FourierTransformInfraredSpectroscopy–ParticleSizeAnalysis–BETSurfaceAreaAnalysis–ThermalAnalyses2–ContactAngleMeasu

3、rement12011/2/13KeyStepsinDevelopingNanomodifiedMaterials•Materialspreparation.•PtPropertychhtaracteriizatition.•Materialperformanceordevicefabrication.ÆDeterminethedegreeandlevelofdispersionofthenanoparticlesinthepolymermatrix.Æ2maincharacterizationprocesses:1.Structureanalysis(microscopic&spectro

4、scopic).2.Propertymeasurements(dependsonapplications).3ChallengesinCharacterizingNano-sizedMaterials•Smallsizeofthereinforcements:–DifficlttoadoptmanDifficulttoadoptmanywell-establishedtechniquesforthemeasurements.–Difficulttomanipulate.•Requiringspecialtechniquesforidentifyingandanalyzingindividua

5、lnanostructures.–Newmethodsandanalyticaltoolsarerequiredtoquantifythepropertiesofindividualnanostrctures.422011/2/13Wide-angleX-rayDiffraction(WAXD)•EveryatominacrystalscattersanX-raybeamincidentuponitinalldirections.•Atomsincrystalsunderaregular,repetitivearrangementwouldresultconstructivelyinterf

6、erenceofthescatteredwaves.•WAXDisacommonthittechniquetochtharacteriizethedegreeofdispersionsofnanoparticles(e.g.clay,GNP,etc.)inpolymerPANalyticalPowderX-raydiffractometermatrix.5BraggEquation•Braggequation:mλ=2di2dsinΘΘ–angleofdiffraction;d–distanceofatomicplanes;m–orderofdiffraction.CB=BD=ABsinΘC

7、BD=2ABsinΘAB–interplanarspacing(d)CBD–multipleoftheX-rays’wavelengthforin-phaseddiffractedrays.632011/2/13InformationfromWAXD•Immiscible(nod-spacingchange)•Decomposed/deintercalated(d-spacingdecrease)•Inter